1. Field of the Invention
The present invention relates generally to the field of enclosures for electronic devices. More particularly, the invention relates to a technique for optically coupling the light produced by a light emitting source housed within an enclosure to the exterior of the enclosure via a light pipe integrated into a cover of the enclosure, the cover enabling a viewer to view the light from multiple viewing angles around the enclosure.
2. Description of the Related Art
Many electronic devices are designed to produce a visual output. The visual output may provide a myriad of information in a myriad of ways. For example, a device may provide text and images on a computer monitor. Alternatively, a device's visual output may be a light to indicate that the device is operating.
The type of visual output used may be dictated by a number of factors, such as the information to be conveyed and the operating environment of the device. For example, a production line may utilize one or more electronic sensors to provide an operator with information regarding the status of production. An electronic sensor may be placed anywhere along the production line. The electronic sensor may be located at floor level, below floor level, or above floor level, depending on the orientation of the production line. Typically, the visual output of a sensor is visible from only one location from the workfloor.
Many electronic devices utilize a light emitting diode (LED) to convey information. In some instances, an LED may be mounted on an exterior surface of an electronic device. However, the LED is more susceptible to damage when mounted on the exterior of an electronic device. Additionally, electrical wiring typically must be routed to the LED to enable it to operate. In some instances, an LED, or LED's, may act as nuisance sources of electro-optical/electro-magnetic noise. LED's also have been mounted on circuit boards housed within a protective enclosure. The light from an LED may be coupled through a window to the outside. Alternatively, a light guide, such as a fiber optic cable, may be used to direct light from the LED to the outside of the enclosure. The assembly of the device is complicated by the need to route the light guide from the LED to a cover of the enclosure. Additionally, in both of these configurations the viewing angle for viewing the light from the LED is limited. In the former, a viewer is only able to see the light from the LED when the viewer is positioned directly in the line of sight of the window and the LED. In the latter, the process of reflecting the light internally through the optical fiber results in the optical fiber effectively producing a unidirectional beam of light. As a result, a viewer located directly across from the fiber optic cable may be able to see the light from the LED but a viewer located on another side of the device may not. In a production environment, where an operator may be constantly changing positions, an electronic device having a visual output with a limited viewing angle may be problematic to production. For example, a production line may have a sensor to detect various operating conditions on the line. The sensor may utilize one or more LED's to indicate these operating conditions to an operator. If the operator cannot see the output of the LED's from the operator's location, either the information will be lost or the operator will have to move to a another location where the output of the LED can be seen.
There is a need, therefore, for an improved technique for optically coupling the light from an LED housed within an enclosure to a viewer located on the outside of the enclosure in a manner that will enable the light to be seen from multiple viewing angles around the electronic device.